kube/postgres: support resources specification, implement graceful shutdown

Change-Id: Iaecf827a43422bd4c59b06e771273624c764f6b3
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1856
Reviewed-by: informatic <informatic@hackerspace.pl>

kube/postgres.libsonnet

@@ -71,6 +71,8 @@ local kube = import "kube.libsonnet";
         # This exists solely for backwards compatibility with old postgres_v libsonnet
         # and should not be used in new deployments
         versionedNames: false,
+
+        resources: {},
     },
 
     safeVersion:: std.strReplace(cfg.version, ".", "-"),
@@ -101,12 +103,20 @@ local kube = import "kube.libsonnet";
                     volumes_: {
                         data: postgres.volumeClaim.volume,
                     },
+                    terminationGracePeriodSeconds: 120,
                     containers_: {
                         postgres: kube.Container(postgres.makeName("postgres")) {
                             image: cfg.image,
                             ports_: {
                                 client: { containerPort: 5432 },
                             },
+                            lifecycle: {
+                                preStop: {
+                                    exec: {
+                                        command: ["/bin/sh", "-c", "pg_ctl stop -w -t 60 -m fast"]
+                                    }
+                                },
+                            },
                             env_: {
                                 POSTGRES_DB: cfg.database,
                                 POSTGRES_USER: cfg.username,
@@ -121,6 +131,7 @@ local kube = import "kube.libsonnet";
                                 std.objectFields(cfg.opts),
                             ),
 
+                            resources: cfg.resources,
                             volumeMounts_: {
                                 data: { mountPath: "/var/lib/postgresql/data" },
                             },